Medical electrical leads or drug delivery catheters (hereafter referred to as therapy devices) are placed in the contact with biological tissue to delivery a therapy to the patient. These therapy devices are part of a system that may include signal or pulse generators (IPGs) or drug delivery pumps or combinations of such. The stimulators or pumps in the system may be external to, or implanted in, the patient.
Medical electrical leads may be used, for example, to delivery electrical energy to various biological tissues such as the heart, brain, or peripheral nervous system, etc. For example, implantable leads, such as the Medtronic Model 3487A lead, have been used for stimulating the dorsal columns of the spinal cord, or implantable leads, such as the Medtronic Model 3587A, have been used for peripheral nerve stimulation.
Medical drug delivery catheters, for example, may be used to delivery therapeutic agents to the intrathecal space of the spinal canal, or to the blood vasculature, or brain ventricles, etc. Catheters such as the Medtronic Model 8703 may be used for these types of applications.
Various lead or catheter anchors or retention systems are described in U.S. Pat. Nos. 5,683,446; 5,746,722; 5,824,032; 5,957,968 and 6,901,287; US published patent application Publication No. 2003/0220678; European Patent Publication No. 1,048,320; and PCT International Publication No. WO 03/099375.